The overall objective is to characterize the effects of PCP, in comparison to other abused drugs, on complex operant behavior in monkeys and pigeons. The first series of experiments will compare PCP with a variety of other drugs reported to have hallucinogenic effects, namely, MDMA, LSD, DMT, psilocybin, mescaline, DOM, ketamine, d-SKF 10047, dexoxadrol, etoxadrol, and scopolamine. The behavioral baseline will be a multiple schedule of repeated acquisition ("learning") and performance of four-response chains in patas monkeys, and dose-effect data will be obtained for each drug. The second series of experiments will use a similar baseline to compare the same drugs in pigeons. In the third and fourth series of experiments, PCP will be compared with four prototype drugs (d-amphetamine, pentobarbital, LSC, and scopolamine) in patas monkeys and pigeons responding in a "memory" task involving repeated acquisition and delayed performance. With this baseline, one can determine the extent to which the subjects can "remember", after varying delays, the particular four-response chain they acquired during a given session. These experiments will also determine whether "overlearning" attenuates the effects of the drugs on retention. The methodology in the proposed research is important because it provides the means for studying drug effects on learning and memory in individual subjects. This point is especially relevant to studying PCP's effects since there are often marked individual differences in the response to PCP in both animals and humans.